Setting Temp in Shower Handle

I recently bought a house that has a Glacier Bay single shower handle. It starts in the off position, which is 6 O'Clock, and moves to Hot, which is 12 O'Clock. Unfortunately, the handle only goes to a position between 2 and 3. Everything is fine with the water hearter and boiler, so I am assuming the issue is with the handle because it will not all the way up to the 12 position.

Before I take off the shower handle and the grout around it, where can I find instructions on how to adjust the water temperature in the handle? Also, when I put it back on do I need to grout around the circular handle plate or can I use some type of caulking?

Hello, NYBubba, I've got the answer to your question. I just spoke to my plumbing Guru, Henry, and he confirmed what I thought to be the solution to you problem. You need to take the handle off and adjust the "stop" inside the faucet. Remove the handle and look inside, you should see some notches. All you need to do is adjust the stop counter clock-wise. This will give you a setting closer to your desired 12:00 o'clock position. Removing everything isn't necessary, just a simple adjustment.

Thank you very much. I did find a red cap that appeared to cut the handle short. Although I cannot get the handle up to the 12 position, it did move up and the water temp has increased. I don't think there is anything else I can do, other than improve the water heater.